As others said, if agile fails, "you were not doing it enoug".

But if agile is criticized... only worse alternatives are given, if at all. Here, spec-driven development is inferior, as in most cases the goal is only vaguely known. Cyclical development is not some hollow mantra, it is how life works. All the rituals around it were just to faciliate more communication. A lot of people in this field just hate that, they want their tickets and to be left alone.

Now that implementation cycles are even shorter, there is even less manual need for coding, agile methodologies will be actually more prevalent.